/*
 * Copyright (C) 2009 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "flutter/sky/engine/platform/transforms/PerspectiveTransformOperation.h"

#include "flutter/sky/engine/platform/animation/AnimationUtilities.h"
#include "flutter/sky/engine/wtf/MathExtras.h"

namespace blink {

PassRefPtr<TransformOperation> PerspectiveTransformOperation::blend(
    const TransformOperation* from,
    double progress,
    bool blendToIdentity) {
  if (from && !from->isSameType(*this))
    return this;

  if (blendToIdentity) {
    double p = blink::blend(
        m_p, 1., progress);  // FIXME: this seems wrong.
                             // https://bugs.webkit.org/show_bug.cgi?id=52700
    return PerspectiveTransformOperation::create(clampToPositiveInteger(p));
  }

  const PerspectiveTransformOperation* fromOp =
      static_cast<const PerspectiveTransformOperation*>(from);

  TransformationMatrix fromT;
  TransformationMatrix toT;
  fromT.applyPerspective(fromOp ? fromOp->m_p : 0);
  toT.applyPerspective(m_p);
  toT.blend(fromT, progress);
  TransformationMatrix::DecomposedType decomp;
  toT.decompose(decomp);

  if (decomp.perspectiveZ) {
    double val = -1.0 / decomp.perspectiveZ;
    return PerspectiveTransformOperation::create(clampToPositiveInteger(val));
  }
  return PerspectiveTransformOperation::create(0);
}

}  // namespace blink
